Systems, devices, and methods for retrieval systems having a tether

ABSTRACT

The embodiments described relate to retrieving temporary Inferior Vena Cava (IVC) filters and other endovascular implants or foreign bodies. Features are provided for effective actuation in closing an inner aperture of the embodiments.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/847,473, filed Dec. 19, 2017, which claims priority to and thebenefit of U.S. Provisional Patent Application Ser. No. 62/438,277,filed Dec. 22, 2016, both of which are incorporated by reference hereinin their entireties for all purposes.

FIELD

The embodiments described herein relate to retrieval devices, someembodiments relate to system and methods for endovascular temporaryInferior Vena Cava (IVC) filters.

BACKGROUND

Temporary IVC filters are placed like permanent filters, but aredesigned so that they may be retrieved in a separate endovascularprocedure, generally from a femoral vein or internal jugular veinapproach. Most of the currently-available temporary filters include ahook-like feature with which they can be captured and received within acatheter or sheath for removal by employing a gooseneck snare or amulti-loop snare.

While retrieval is a simple procedure in principle, difficulty is oftenencountered capturing a filter's hook with the snare loop(s). Suchdifficulty is compounded when the filter is tilted or off-kilter inplacement. Several filters are designed to avoid such orientation.

However, the problem remains common because the device is not anchoredinto the IVC in a stable fashion. Constant blood flow in addition toblood clots can disorient the filter within the IVC making recapturedifficult. Accordingly, there exists a need for a filter retrievalsystem with improved ease of use and/or less susceptibility to problemsof filter orientation.

SUMMARY

Example embodiments of systems, devices, and methods for an elongateretrieval device having a tether are provided. In many embodiments, theelongate retrieval device includes a braid structure at the distal endof an elongate shaft, the proximal end of which is accessible to theuser directly or by way of a proximal user interface (e.g., a controlhandle). The braid structure can include one or more layers of braid,and in many embodiments, is configured as a funnel having an interiorflap, such that the funnel has a distal opening that is relativelylarger than a proximal opening at the proximal edge of the flap.

In many embodiments, one or more tethers can be located at or near theproximal opening. The one or more tethers can have variousconfigurations. In some embodiments, a portion of a tether passesthrough the braid at the proximal opening and extends across theproximal opening (e.g., like a diameter or chord of a circle or ellipse)in a configuration crossing the proximal opening. In some embodiments,portions of one or more tethers can be arranged to cross both theproximal opening and each other in a symmetrical crossing configuration(e.g., at right angles like a cross-hair in the case of two tetherportions) or a non-symmetrical crossing configuration (e.g., where twotether portions cross at non-perpendicular angles). The tether portionsof the crossing configuration can also extend at least partially aroundthe peripheral rim of the proximal opening. In some embodiments, aportion of a tether can extend at least partially around the proximalopening, with or without one or more tether portions in a crossingconfiguration. Additional embodiments are disclosed, includingadditional embodiments of systems utilizing retrieval devices, andmethods of using such systems and/or devices to retrieve a foreign bodyfrom within a patient.

Other systems, devices, methods, features and advantages of the subjectmatter described herein will be or will become apparent to one withskill in the art upon examination of the following figures and detaileddescription. It is intended that all such additional systems, devices,methods, features and advantages be included within this description, bewithin the scope of the subject matter described herein, and beprotected by the accompanying claims. In no way should the features ofthe example embodiments be construed as limiting the appended claims,absent express recitation of those features in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The details of the subject matter set forth herein, both as to itsstructure and operation, may be apparent by study of the accompanyingfigures, in which like reference numerals refer to like parts. Thecomponents in the figures are not necessarily to scale, emphasis insteadbeing placed upon illustrating the principles of the subject matter.Moreover, all illustrations are intended to convey concepts, whererelative sizes, shapes and other detailed attributes may be illustratedschematically rather than literally or precisely.

FIGS. 1A and 1B depicts examples of IVC filters usable with the systemsand/or methods hereof.

FIG. 2 is a side view depicting an example embodiment of a retrievalsystem.

FIG. 3 is a side-sectional view depicting another example embodiment ofa retrieval system.

FIG. 4 is an end-view depicting an example embodiment of the braidedportion of a retrieval device.

FIG. 5 is a partial side-sectional view depicting an example embodimentof a retrieval system.

FIG. 6 is a side-sectional view depicting an example embodiment of auser interface for a retrieval device.

FIGS. 7A-7C depict example embodiments of strand patterns.

FIGS. 8A and 8B are partial side-sectional views depicting exampleembodiments of retrieval devices with different proximal aperture or rimsupport-strut configurations.

DETAILED DESCRIPTION

Various exemplary embodiments are described below. Reference is made tothese examples in a non-limiting sense, as it should be noted that theyare provided to illustrate more broadly applicable aspects of thedevices, systems and methods. Various changes may be made to theseembodiments and equivalents may be substituted without departing fromthe true spirit and scope of the various embodiments. In addition, manymodifications may be made to adapt a particular situation, material,composition of matter, process, process act(s) or step(s) to theobjective(s), spirit or scope of the present invention. All suchmodifications are intended to be within the scope of the claims madeherein.

Before the present subject matter is described in detail, it is to beunderstood that this disclosure is not limited to the particular exampleembodiments described, as such may, of course, vary. It is also to beunderstood that the terminology used herein is for the purpose ofdescribing particular embodiments only, and is not intended to belimiting, since the scope of the present disclosure will be limited onlyby the appended claims.

All features, elements, components, functions, and steps described withrespect to any embodiment provided herein are intended to be freelycombinable and substitutable with those from any other embodiment. If acertain feature, element, component, function, or step is described withrespect to only one embodiment, then it should be understood that thatfeature, element, component, function, or step can be used with everyother embodiment described herein unless explicitly stated otherwise.This paragraph therefore serves as antecedent basis and written supportfor the introduction of claims, at any time, that combine features,elements, components, functions, and steps from different embodiments,or that substitute features, elements, components, functions, and stepsfrom one embodiment with those of another, even if the followingdescription does not explicitly state, in a particular instance, thatsuch combinations or substitutions are possible. Express recitation ofevery possible combination and substitution is overly burdensome,especially given that the permissibility of each and every suchcombination and substitution will be readily recognized by those ofordinary skill in the art upon reading this description.

Example embodiments of IVC filter/object retrieval system with improvedusability and with less susceptibility to the object's (e.g., IVCfilter) orientation issues are disclosed. In some embodiments, the IVCobject retrieval system may be used with a wide variety of filterarchitectures—existing or otherwise. Accordingly, new filters may bedesigned for use with the disclosed IVC object retrieval system in whichfewer design constraints and/or compromises may be required of thefilter design. By way of example only, and not to limit the devices withwhich the embodiments of retrieval systems described herein may be used,examples of filters with which the present embodiments can be used forretrieval or other purposes include existing and/or modified versions ofthe filters described in any of U.S. Pat. Nos. 3,952,747; 5,601,595;6,443,972; 7,338,512 and 7,625,390 (all of which are incorporated hereinby reference in their entireties for all purposes), with commerciallyreleased devices including the OPTEASE, GUNTHER, TULIP, CELECT, DENALIand OPTION, or with others.

Many embodiments of the IVC object retrieval systems include afunnel-shaped apparatus at their distal end. The funnel trap may beconstructed of heatset braid, e.g., superelastic (SE) nickel-titaniumalloy (nitinol) braid. In some embodiments, the funnel-shaped end of aretrieval device may include a distal rim defining a distal opening, anda more proximal aperture or opening defined at a proximal end of aninner portion (e.g., a flap). When an enlarged proximal end of an IVCfilter or other foreign body to be captured is guided past the distalrim of the funnel and through the proximal aperture, the proximalaperture can then be closed (e.g., by cinching) to effect capture of thefilter or other foreign body.

In some embodiments, the retrieval system includes loop-type featuresthat are actuatable to close the proximal aperture. As described incommonly-owned PCT Application No. PCT/US15/65102 (United StatesPublication No. 2016/0095689) a strand of material may be used to extendas a tether to the proximal end of the retrieval system for actuation.Example of spliced-loop lasso and tether systems are described therein.

In some embodiments, the retrieval system includes an aperture actuationapparatus having a non-spliced or two-ended loop, which provides betteror more effective aperture actuation. The non-spliced or two-ended looplasso provides a more complete aperture or opening closure, with lessrequired user input (in terms of length to pull and/or force to actuate)to close aperture.

In some embodiments, the non-spliced (or two-ended) loop is formed by alength of tether (e.g., a suture, cord, fiber or filament, formed from,e.g., polymeric, metallic (e.g., nitinol) or a hybrid or compositematerials, or others) with two free ends. To add stability to the loopstructure, one or both ends of the tether may pass or cross throughopposite-side strand material adjacent the loop opening. This canultimately yield a two-ended tether setup for the loop. The non-splicedloop can offer the added benefit of tether members acting in parallel(e.g., as in a parallel spring arrangement) to limit stretch associatedwith forceful system manipulation.

In some embodiments, the retrieval system may include a crossingstructure of tether material or other filament(s) at the proximalaperture. In certain embodiments, the crossing structure is a separatefeature are not integrated with the encircling lasso. Separating thecrossing structure (e.g., cross-hairs) from the loop allows for theirindependent actuation and associated improvement in proximal apertureclosure.

With separate loop and cross-hair features, the tethers can, in someembodiments, be arranged as four solo strands. In some embodiments, thetether of the retrieval system may include two sets (e.g., two strandswith two ends). In other embodiments, a tripod configuration may beformed using a set of two tethers (those for the loop) and two others(those for the cross-hairs). These embodiments offer a measure ofsymmetry in applying tension (or resisting tension) around the apertureas compared to single-tether approaches. In some embodiments, theretrieval system may employ two, three and four legged symmetry options.Stated otherwise, 2-way, 3-way and 4-way symmetry tethering systems maybe employed. Or still further, options are provided with bilateral,trilateral and/or quadrilateral symmetry.

In the embodiments with the two sets of strands, these sets of strandsmay be synergistically employed in connection with a pair of additionalsupport struts. A first pair of tether strands may be received within afirst tubular support strut and a second pair of tether strands may bereceived in a second tubular support strut, the struts may be sized sothat tether pull that would otherwise draw the inner flap and proximalaperture inward (or more proximally) is supported to avoid such action.By maintaining proximal aperture position with the system, bowing of theoverall funnel construct that can otherwise occur is limited.

Various construction embodiments for the support struts are presentedbelow. Likewise, the support struts may be used in configurations otherthan the paired option. A single support strut may be employed.

Another optional set of features concern the manner of tether attachmentand/or configuration within the system. The incorporated Int'l Publ. No.PCT/US15/65102 (United States Publication No. 2016/0095689) shows anddescribes tethers glued or potted at a proximal end of the device. Insome embodiments, the tether(s) may be connected to a core member thatextends from the proximal end to at least mid-way or more preferably towithin at least about 2 to 10 cm of the distal end of the device. Such acore member is configured (e.g., by material selection and/or physicalgeometry) to be stiffer or offer less elasticity than the otherwisefull-length tether material. In some embodiments, the tether strands maybe attached to a polyethylethylketone (PEEK) rod. Using a polymer rod ortube allows it to be easily cut-through, which can provide a “bail out”feature by removing tether tension to open the aperture for releasing anembedded foreign object (such as a “stuck” IVC filter). In someembodiments, a metal wire core member (e.g., stainless steel, CoCr ornitinol) could likewise be used.

In some embodiments, applying tension on the tethers may cause theproximal opening (or aperture) to close and releasing the tension maycause the proximal opening to re-open from the closed position.

In some embodiments, the retrieval system includes a tensioning andde-tensioning mechanism that includes multiple tethers. The multipletethers could be twisted around or relative to each other to shortentheir effective length and tighten the lasso and/or cross-hairsassociated with the proximal aperture. The multiple tethers tensioningand de-tensioning mechanism is highly controllable in that each fullturn adds a fine gradation of axial tension and/or movement. Moreover,the same twisting approach to tighten the tethers and aperture in aforeign-object retrieval procedure can be applied in manufacture forpre-loading and/or removing unwanted slack from the lasso and/orcross-hairs.

The multiple tethers tensioning and de-tensioning mechanism also servesas an actuation mechanism (or user interface) that is both accurate andwith tactile-feedback without complex machining, gearing or other userinterface requirements. The actuation mechanism may be actuated byapplying torque or to twist-up the tethers (directly or via anintermediate shaft such as described above).

In some embodiments, a user interface is threaded and works inconjunction with the twist-up of the suture strand(s). By applyingtreads or threading to interfacing members, a hybrid actuation system iscreated. It is hybrid in the sense that the combination of tether twistand tread advancement (or retraction) controls aperture actuation. Sucha system may easily incorporate a hemostatic and/or a detent or clickerfeature for audibly and/or tactically counting actuation turns.

The subject delivery and/or retrieval devices, kits in which they areincluded (with and without assembly), methods of use and manufacture(including assembly of the constituent components in vivo or ex vivo)are all included within the scope of the present disclosure. Someaspects of the same are described above, and more detailed discussion ispresented in connection with the figures below.

FIG. 1A shows a GUNTHER TULIP (Cook Medical, Inc.) temporary IVC filter10 with a retrieval interface 12 configured with a hook end. FIG. 1Bshows an IVC filter 10 where, instead of a hook, the retrieval interface12 of IVC filter 10 has a nubbin-type interface 22. The nubbin (itself)may comprise a laser-formed or solder-formed protuberance or bump 24 onan extension 26 from a hub 28. Alternatively, as shown in FIG. 2 ,filter retrieval interface 12 may comprise a band 24′ (e.g., a Pt markerband) mounted (e.g., by swaging, welding, gluing, etc.) on extension 26.

FIG. 2 provides an overview of a retrieval system 100 in which thefeatures further described may be incorporated, in accordance withvarious embodiments of the disclosure. Retrieval system 100 includes afunnel-trap structure 30, which may be made of a heatset braid material32. In some embodiments, funnel-trap structure 30 may be a flexibledistal extension to an elongate shaft 34, which can (in someembodiments) be slidably positioned within an elongate sleeve 50. Insome embodiments, elongate sleeve 50, which may be a commerciallyavailable catheter or sheath or a custom part of retrieval system 100configured for advancement through the patient's vasculature, mayinclude a distal radiopaque marker band 52. In some embodiments,elongate sleeve 50 can be omitted or otherwise configured to remainoutside of the patient's body.

In some embodiments, braid 32 may comprise nitinol (e.g., such as thatwhich is superelastic (SE) at human body temperature), CoCr, StainlessSteel or another biocompatible material. Braid 32 may comprise ofmaterial having between 72 and 288, or between about 144 and 192filament “ends” in a 1-over-1, 1-over-2, 2-over-2 or other pattern. Insome embodiment, the SE nitinol wire may be between about 0.001 andabout 0.002 inches in diameter. At this diameter range, a mesh of SEnitinol wire provides a supple and relatively “smooth” matrix surfacefrom which to construct the flexible funnel-trap. The value of such asurface is in its atraumatic aspect and/or ability to help guide an IVCfilter interface or other foreign body to be captured into position forcapture even if it is oriented off-angle. Still, other wire sizes and/orend counts in a braid or other construction options are possible aswell.

To assist with target device or foreign body capture or recapture,funnel trap structure 30 may be selectively directable. As indicated bythe arrows in FIG. 2 , the material from which structure 30 is made canbe heatset or otherwise configured to provide a bias in an angulardirection. The angle of deployment of structure 30 may be selectable orfully straightened by relative position of a core member or obturator(not shown) or by a sleeve or catheter sheath. Further positioning maybe achieved by rotating the device as further illustrated.Alternatively, sleeve 50 may be shaped to flex shaft 34 to set trapstructure 30 position.

Trap structure 30 may be generally frusto-conical in shape as shown orotherwise configured. With an outer conical shape (e.g., a triangularshape in cross section as shown in FIG. 3 ) structure 30 is highlysupportive, yet provides a flexible “waist” section 48 for thedirectable feature options noted above. Still, the device may be bowedoutward along its sides or otherwise configured.

In some embodiments, a distal rim opening (or aperture) 40 of structure30 may be larger than its proximal rim opening 42 to create a structurethat tapers down in the distal to proximal direction. In this way,filter engagement feature 24′ (as shown in FIG. 2 ) of device 10 (e.g.,an IVC filter) may be guided along braid material 32 and throughproximal opening 42. Once the end of device 10 has passed throughopening 42, and optionally bottomed-out at or near section 48, it can bereleasably captured and retained by reducing the width of openings 40and/or 42 (e.g., at least partially closing or constricting openings 40and/or 42). Such action is further described below. In some embodiments,a pocket (P) may be formed within the substantially conical orfrusto-conical braid wall 44.

In some embodiments, upon capturing device 10, structure 30 can bewithdrawn from the patient's body without first retracting structure 30into an outer sleeve (e.g., device 50) and then withdrawing from thebody through an introducer sheath located at the percutaneous opening.In other embodiments, after capturing device 10, structure 30 can bewithdrawn into sleeve 50 and then device 10, structure 30, and sleeve 50can be withdrawn together through an introducer sheath and out of thepatient's body. The retrieval process may be visualized fluoroscopicallyby a physician during the medical procedure.

In some embodiments, the catheter or pusher shaft 34, sleeve 50 or othercatheters or sheaths used in or with the system may comprise of medicalgrade plastics such as PTFE, FEP, PEEK, PI, etc. Alternatively, they maybe constructed using conventional catheter construction techniques andinclude a liner, braid support and outer jacket (not shown), metalhypotube, etc. In embodiments intended for tracking through a guide ordelivery catheter without an incorporated sheath, a loading sheath maybe employed. Any such loading sheath may be pre-split or splittable.Other typical percutaneous access instruments (such as wires, etc.),valves and other hardware may also be employed in accordance withvarious embodiments, including medical treatment methods.

Trap structure 30 can be made as a subassembly and attached to itscatheter or pusher shaft 34. U.S. Publ. No. 2016/0095690 and U.S. Publ.No. 2015/0105819, both of which are incorporated by reference in theirentireties for all purposes, describe example embodiments of steps inthe manufacture of a braid portion 30 of device 100.

Structure 30 can include one or more layers of braid 32. FIG. 3 is across-sectional view depicting an example embodiment of structure 30having an inner layer 32A and an outer layer 32B of braid. In someembodiments, layers 32A and 32B are formed by fastening or securing twodiscrete layers of braid together (e.g., by adhesive, by one or moreconnectors, etc.). In the embodiment depicted here, braid 32 is onecontinuous sheet or tube of braid that is folded back over itself toform the two layers 32A and 32B. The position where braid 32 is foldedback upon itself to form the two layers is indicated by referencenumeral 38, and can be referred to as a first fold in braid 32. The twolayers 32A and 32B of braid 32 can also be folded at a second location,indicated by reference numeral 36, which can be referred to as a secondfold in braid 32. Configuration in this manner results in an innerfunnel or flap 46 within an outer funnel formed by braid wall 44.

In the embodiment of FIG. 3 , the peripheral rim of distal opening 40 isformed by second fold 36 and the peripheral rim of proximal opening 42is formed by first fold 38. Inner layer 32A and outer layer 32B of braid32 can be set in the shape depicted in FIG. 3 by heat-setting usingconventional techniques (e.g., in a furnace, salt pot, etc.). In manyembodiments, distal opening 40 is larger than proximal opening 42,although other configurations are possible.

In some embodiments, for IVC filter retrieval, braid portion ofstructure 30 may have a diameter (D) from about 5 mm to about 20 mm, ormore preferably about 10 to about 15 mm (e.g., size in a range to workwithin average size human IVCs where such vessels are reported as havinga mean diameter of 20 mm within a range of 13 to 30 mm). The braidportion may have a length (L) ranging from about 10 mm to about 30 mm).Structure 30 may have an overall cone angle (α) (between braid walls 44)ranging between 30 to 90 degrees. In some embodiments, an angle (β) ofbend 36 between braid wall 44 and flap 46 may be between about 0 andabout 60 degrees, and flap length (F) may be between about 1 and about10 mm in length.

Distal opening 40 may have a diameter (d) between about 1.5 and 4 mm. Insome embodiments, the diameter of distal opening 40 may be between 2.5-3mm (for retrieving commercially-available IVC filter devices). Distalopening 40 of structure 30 may be set perpendicularly relative to adevice axis. Otherwise, it may be angled or have a more complex shape.

FIG. 4 is an end-on view of an example embodiment of structure 30. Inthis embodiment, structure 30 includes a support member having elongatemembers 60A, 60B, 60C, 60D, 60E, 60F, and 60G. Any number of one or moreelongate members 60 can be used. In embodiments where structure 30includes multiple braid layers 32A and 32B, the support member(s) can beinterposed between braid layers 32A and 32B. Support members 60 canadditionally, or alternatively, be located on the inner-most side ofinner braid layer 32A as shown in FIG. 5 , which is a partialcross-sectional view depicting another example embodiment of device 100.Further optional details of support member construction and/or placementare presented in Int'l Publ. No. WO 2016/094676, which is incorporatedby reference herein in its entirety for all purposes.

FIG. 4 also shows a crossing arrangement 74 of a tether 76 formed fromsuture material (e.g., ultra-high-molecular-weight polyethylene (UHMWPE)suture) extending across the inner proximal aperture 42 of the braid inaccordance with some embodiments of the disclosure. In some embodiments,the strands are symmetrical, resembling a crossing configuration 72. Anysymmetrical or non-symmetrical crossing configuration can be used. Here,one section of a tether 76 is arranged to twice bisect proximal opening42 at right angles. In some embodiments, only a single tether sectioncan extend across proximal opening 42, e.g., such in the form of adiameter or chord of a circle, where no second tether section norcrossing pattern is implemented. In other embodiments, a first discretetether section (having two ends) can extend across proximal opening 42and a second discrete tether section (having two different ends) canextend across proximal opening 42 such that the two discrete tethersections form the crossing configuration 72.

Another section of tether 76 can be used to form a loop configuration 74that at least partially encircles (here the loop fully encircles)proximal opening 42. Loop configuration 74 is shown positioned outsideof crossing configuration 72 for ease of illustration, where in practiceloop configuration 74 will be in contact with or in close proximity toinnermost braid at proximal opening 42. In one embodiment, a singlesection of tether (having two ends) is woven through proximal opening 42to form both the crossing configuration 72 and loop configuration 74.

In the embodiment of FIG. 5 , the position of (at least some) of tethers76 can be seen between braid layers 32A and 32B at or adjacent toproximal opening 42 (e.g., at or near the internal radius thereof). Insome embodiments, one or more tethers 76 form cross-hair 72 and/or loop74 configurations at the distal opening 40 and/or proximal opening 42and then the one or more tethers 76 extend proximally towards and/orinto shaft 34. Tethers 76 can be used to constrict or allow expansion ofopenings 40 and/or 42. Here, two tethers 76A and 76B are shown coupledwith proximal opening 42, although others may be included as will bedescribed in more detail herein.

Tethers 76A and 76B can hold the inner flap 46 from pulling out oreverting, for example, in the event of forceful device withdrawal wherethe medical device to be captured is one that includes a hook interface12. Tethers 76A and 76B can also provide a mechanism for actuatingclosure of opening or aperture 42.

As shown in FIG. 5 , tethers 76A and 76B are connected to a core member80 (which may be tube, wire or rod) positioned within shaft 34. Thetethers may be glued in a slot, across flats and/or located within anoverlying sheath or cover 82 receiving adhesive to effect connection.

Tethers 76A and 76B can be pulled or tensioned using core member 80 totighten down the associated loop 74 and/or cross-hair 72 features. Insome embodiments, core member 80 is omitted and tethers 76A and 76Bextend to the proximal end of the device to user interface such as aslide or gear-type device handle. However, core member 80 is useful inthat is can be configured to provide greater stiffness (less elasticity)than full-length suture tether(s). In some embodiments, cross-hairconfiguration 72 is present at proximal opening 42, while loopconfiguration 74 is present at distal opening 40. In still furtherembodiments, loop configurations 74 are present at both distal opening40 and proximal opening 42, while a cross-hair configuration is presentat proximal opening 42. In still further embodiments, both distalopening 40 and proximal opening 42 have both cross-hair 72 and loop 74configurations.

Also, core member 80 can provide a stable user-interface platform aswell as surface area against which to form a seal. With core member 80extending from the proximal end of shaft 34, it offers a position toaffix a standard torquer 84.

With a torquer tightened down and connected to core member 34, twistingthe parts together while stabilizing shaft 34 transfers rotation totethers 76. The twisting (like twisting up a common playground swing)results in tether shortening or tensioning that is applied to the loopand/or cross-hairs.

The number of rotations applied using the torquer can be counted byincluding a visual guide or cue on the torquer (such as blacked-outregion 86 optionally formed by laser etching or engraving). A sealcomplex (comprising a pair of sleeves 90A, 90B affixed to core member todefine an O-ring groove, an O-ring 92 in that groove and a stop 94 thatis press-fit or glued into sleeve 34) is advantageously provided aswell.

System 100 in FIG. 5 shows two tethers 76A and 76B. However, it shouldbe understood that the perspective shown might be illustrative of twogrouped pairs of tethers or four tethers—with only half of them showingdue to the sectional nature of the view. As detailed further below,other tether configurations are possible as well.

FIG. 6 depicts an example embodiment of a user interface 200 that can bemanually held by the user outside of the patient's body. As in system100, a concentric arrangement of a core member 80 and a shaft sleeve 34are shown. Core member 80 may extend outside shaft 34. Also, provisionis made for an O-ring 202 (shown compressed) in a groove 204. However,O-ring 202 may be relatively larger than in the FIG. 5 assembly. This ispossible without compromising system profile as groove 204 in thisconfiguration is between a proximal end or face 206 and a wall 208 of asleeve 210.

Sleeve 210 may include threading 212 that mates or matches with that ofan outer torquer body 214, which may include a knurled or checkeredpattern 216 for user grip.

Torquer body 214 may be connected to core member 80 with adhesive 218 orby other means. Threaded sleeve 210 may be connected to shaft 34 byadhesive 220 or other means. When turning torquer body 214 and grippingshaft 34 (which may also be textured for improved grip, such as by mediablasting), torquer body 214 either advances distally or retractsproximally with the direction of the threading. To count or otherwisetrack the number or revolutions or turns applied, the components can betactically and/or audibly counted by incorporating a detent or clickfeature(s) in the gap (G) between sleeve 210 and torquer body 214.

In some embodiments, torquer body 214 may be turned (e.g., clockwiseemploying left-handed threads) so that it pulls back (e.g., movesproximally) while the tethers are also being twisted, which results inthe closing or constricting of opening 42. As such, significantly fewerturns with system 200 are needed to tighten the aperture loop 74 and/orcross-hairs 72 as compared to other closing methods where the torquer issetup only to rotate.

Depending on the thread pitch selected (e.g., 4-40 standard or M1threads), highly accurate adjustment can be made. Essentially, by“counting turns or partial turns” a physician can actually observe andprecisely control device actuation under fluoroscopy during a medicalprocedure. The same holds true for the system in FIG. 4 , but itrequires additional actuation turns for the desired level of apertureclosure for certain IVC filter capture. The sub-system in FIG. 4 can beconfigured for equivalent tether tensioning and aperture closure withabout half, a third or even a quarter as many turns.

In both embodiments (e.g., system 100 in FIG. 5 and system or sub-system200 in FIG. 6 ), internal friction (e.g., as provided in predictablefashion by the O-ring or such other seal architecture as may beemployed) between various components of the system prevents “back-drive”or inadvertent untwisting once tension is applied. However,intentionally reversing or “taking turns off” of the torquer body 84 or214 will cause it to untwist the tethers. This allows loosening atopening or aperture 42 and release of a captured implant, if desired.With the threading included between sleeve 210 and torquer body 214, thecore member is also advanced—with such combined action (e.g., withtranslation) causing such a result with fewer turns (e.g., as withtightening above).

Accordingly, system 200 may be regarded as a type of hybrid userinterface. It is hybrid in the sense that it uses threads/threading foraxial or translative action in conjunction with the twist-up tighteningoption also described.

Turning now to FIGS. 7A-7C, these figures illustrate different loop 74and cross-hair (or X-shaped) 72 sewing or threading patterns forlocation at or adjacent to proximal opening 42. The configuration ofloop 74 can extend entirely around proximal opening 42 (FIG. 7A),substantially entirely around proximal opening 42 (FIG. 7C), orpartially around proximal opening 42 (FIG. 7B). Typically, loop 74 willbe fit or located between braid layers 32A and 32B at first fold 38. Thetethers that form the cross-hair configuration (or any other crossingpattern) may be located above or below loop 74 at or adjacent toproximal opening 42.

As shown in FIGS. 7A-7C, the exit directions of each tether strandsaround proximal opening 42 may be at the same location at differentlocations. In some embodiments, one or more of the tether strands crossover and bend around the adjacent braid toward the proximal end (userinterface end). In some embodiments, as shown in FIG. 7A, one of thestrands may pass through another at a crossing point 78 in the loopconfiguration. Alternatively, this pass-through feature may be omittedand each strand is simply adjacent to each other.

Referring to FIG. 7B, the material defining cross-hairs 72 is partiallyincorporated in defining loop 74 in the lower-left quadrant. The meetingpoints of strands (e.g., 76A/76D and 76B/76C) may involve piercedcrossing points or a twisted, woven or intertwining approach as shown.Proximally directed force (e.g., pull) on each of the four tetherseffects independent tightening of each length interacting withopening/aperture 42.

With the approach in FIG. 7C, two pairs of tethers (76A/76B and 76C/76D)may exit loop 74 at opposite sides. This configuration offers severaladvantages. In some embodiments (as shown FIG. 8A), each paired set oftethers can be received within a support sleeve or strut 90A, 90B.Configured as shown, the struts “float” as they are held in place by theconcentric arrangement of the tether sections.

In some embodiments, each strut is abutted proximally at the distal endof shaft 34 and distally at the rim of proximal opening 42. When thetethers are pulled, the rim remains stable in position, with the strutsin compression and tether tension transmitted to the loop and/orcross-hairs to at least partially close opening 42.

To improve strut fit, the struts may be ovalized or flattened alongtheir length. Such a configuration allows for side-by-side suturereception and/or minimal combined width (W) where the pieces cometogether (e.g., proximally within the trap section 30 when deployed, butalong their entire length when collapsed in sheath 50).

Other construction options are possible as well. For example, the strutsmay be formed by extending and bisecting sleeve 34 and covering thoseportions with thin walled (e.g., 0.003-0.005 inch) tubing. In such anarrangement, the sleeves will contain the tethers and the shaftextensions will be bear compressive load(s).

Without the struts, support members 60A, 60B, etc. may be included inthe construct such as shown in FIGS. 4 and 5 . Or both support member(s)60 and the strut(s) 90 may be employed (although not shown) incombination.

FIG. 8B illustrates another support strut configuration in accordancewith some embodiments. In this case, as single support column isprovided as an intact extension of shaft 34. The extension (E) may becurved, canted or bent, or incorporate a switch-back or S-turn so thatits end 92 does not align with the center of opening 42. However, thisis an option as are other (associated) possible cross-hairs and/or loopconfigurations. As shown, only two tethers 76A and 76B are provided inthis example. They may synch a two-ended loop, alone, to close opening42 or be otherwise used.

The embodiments described herein are restated and expanded upon in thefollowing paragraphs without explicit reference to the figures. In manyexample embodiments, an endovascular medical device is provided thatincludes an elongate shaft connected to a flexible distal extensionincluding a braid, the braid having a distal rim defining a distalopening and a proximal rim defining a proximal opening, where the shaftand the flexible distal extension are configured for insertion intovasculature of a patient; a portion of a tether extending through thebraid at the proximal rim across the proximal opening; and a proximaluser interface configured to tension the tether.

In some embodiments, the braid has a first fold that forms two layers ofthe braid, and the two layers have a second fold, where the second foldis at the distal rim of a funnel-shaped structure and the first fold isat the proximal rim of the funnel-shaped structure. In some embodiments,the portion of the tether extends across the proximal opening twice in acrossing configuration.

In some embodiments, the portion of the tether is a portion of a firsttether, and the medical device further includes a portion of a secondtether arranged as a loop at least partially encircling the proximalrim. The portion of the second tether can be arranged as a loop betweenthe two layers of braid. In some embodiments, the portion of the secondtether fully encircles the proximal opening.

In some embodiments, the first tether has two ends, and the secondtether has two ends, the two ends of the first tether being receivedwithin a first tubular strut, and the two ends of the second tetherbeing received within a second tubular strut. The first and secondtubular struts can be positioned between the proximal opening of theflexible distal extension and a distal end of the elongate shaft.

In some embodiments, the medical device further includes a core memberreceived within the shaft, wherein the tether is connected at a distalend of the core member. The proximal user interface can include atorquer connected or affixed to the core member. The medical device canfurther include an externally threaded interface, where the torquer isinternally threaded. In some embodiments, the medical device furtherincludes a sleeve connected at a proximal end of the elongate shaft, thesleeve including the externally threaded interface.

In some embodiments, the first tether and second tether extendproximally from the proximal opening toward the proximal user interface.In some embodiments, the second tether crosses the proximal openingtwice to form a right angle crossing configuration.

In some embodiments, the proximal opening is configured to capture aretrieval interface of an inferior vena cava (IVC) filter.

In many embodiments, a medical method for retrieving a foreign body isprovided, the medical method including: advancing an endovascularmedical device in a patient's vasculature, the medical devicecomprising: an elongate shaft connected to a flexible distal extensioncomprising a braid, the braid having a distal rim defining a distalopening and a proximal rim defining a proximal opening; a portion of atether extending through the braid at the proximal rim across theproximal opening; passing a portion of the foreign body to be retrievedthrough the proximal opening; and tensioning the tether with the foreignbody extending through the proximal opening.

In some embodiments, the method further includes twisting opposite endsof the tether around each other to achieve the tensioning. In someembodiments, the method further includes supporting the proximal openingwith at least one strut during the tensioning.

In some embodiments, the method further includes withdrawing the foreignbody from the patient's vasculature with the endovascular medicaldevice.

In some embodiments, the tether is a first tether in a crossingconfiguration, the endovascular medical device further comprising asecond tether in a loop configuration around the proximal rim. In someembodiments, the method further includes tensioning the first tether andthe second tether with the foreign body extending through the proximalopening.

In some embodiments, the foreign body is an inferior vena cava (IVC)filter and the portion of the foreign body is a retrieval interface ofthe IVC filter.

The subject methods, including methods of use and/or manufacture, may becarried out in any order of the events which is logically possible, aswell as any recited order of events. Embodiment methods may include anyof a hospital staffs activities associated with device provision,implant positioning, re-positioning, implant or device retrieval and/orrelease.

Furthermore, where a range of values is provided, it is understood thatevery intervening value, between the upper and lower limit of that rangeand any other stated or intervening value in the stated range isencompassed within the invention. Also, it is contemplated that anyoptional feature of the inventive variations described may be set forthand claimed independently, or in combination with any one or more of thefeatures described herein.

Though the invention has been described in reference to severalexamples, optionally incorporating various features, the invention isnot to be limited to that which is described or indicated ascontemplated with respect to each variation of the invention. Variouschanges may be made to the invention described and equivalents (whetherrecited herein or not included for the sake of some brevity) may besubstituted without departing from the true spirit and scope of theinvention.

Reference to a singular item includes the possibility of a plurality ofthe same items present. More specifically, as used herein and in theappended claims, the singular forms “a,” “an,” “said,” and “the” includeplural referents unless specifically stated otherwise. In other words,use of the articles allow for “at least one” of the subject item in thedescription above as well as the claims below. It is further noted thatthe claims may be drafted to exclude any optional element. As such, thisstatement is intended to serve as antecedent basis for use of suchexclusive terminology as “solely,” “only” and the like in connectionwith the recitation of claim elements, or use of a “negative”limitation.

Without the use of such exclusive terminology, the term “comprising” inthe claims shall allow for the inclusion of any additionalelement—irrespective of whether a given number of elements areenumerated in the claim, or the addition of a feature could be regardedas transforming the nature of an element set forth in the claims. Exceptas specifically defined herein, all technical and scientific terms usedherein are to be given as broad a commonly understood meaning aspossible while maintaining claim validity. Accordingly, the breadth ofthe different inventive embodiments or aspects described herein is notto be limited to the examples provided and/or the subject specification,but rather only by the scope of the issued claim language.

The invention claimed is:
 1. An endovascular medical device comprising:a funnel-shaped braid structure having a distal portion folded backinwardly to form a distal opening and a proximal opening; an elongateshaft coupled to the funnel-shaped braid structure; and a first tethercoupled to a portion of a rim of the proximal opening and to a proximaluser interface, the first tether extending across the proximal openingin a crossing configuration, wherein the first tether is configured toconstrict the proximal opening when the proximal user interface isactuated.
 2. The endovascular medical device of claim 1, wherein thefirst tether is disposed between layers of braid.
 3. The endovascularmedical device of claim 1, further comprising a core member receivedwithin the elongate shaft, wherein the tether is connected at a distalend of the core member.
 4. The endovascular medical device of claim 3,wherein the proximal user interface comprises a torquer connected to thecore member.
 5. The endovascular medical device of claim 4, wherein thetorquer comprises internal threads.
 6. The endovascular medical deviceof claim 5, further comprising a sleeve connected at a proximal end ofthe elongate shaft, the sleeve comprises an externally threadedinterface.
 7. An endovascular medical device comprising: a funnel-shapedbraid structure having a distal portion folded back inwardly to form adistal opening and a proximal opening; an elongate shaft coupled to thefunnel-shaped braid structure; a first tether coupled to a portion of arim of the proximal opening and to a proximal user interface, whereinthe first tether is configured to constrict the proximal opening whenthe proximal user interface is actuated; and a second tether at leastpartially encircling the rim of the proximal opening, the second tethercrosses the proximal opening twice to form a right-angle crossingconfiguration.
 8. The endovascular medical device of claim 7, whereinthe second tether fully encircles the proximal opening.
 9. Theendovascular medical device of claim 7, wherein the second tether isdisposed between layers of braid.
 10. The endovascular medical device ofclaim 7, wherein the first tether and second tether extend proximallyfrom the proximal opening toward the proximal user interface.
 11. Theendovascular medical device of claim 7, further comprising a first andsecond tubular strut, wherein the first tether comprises two ends beingthreaded through the first tubular strut, and the second tethercomprises two ends being threaded through the second tubular strut. 12.The endovascular medical device of claim 7, further comprising first andsecond tubular struts positioned between the proximal opening and adistal end of the elongate shaft.